From ed6cd6a17896561b9f51ab4c0d9bbb29e762b597 Mon Sep 17 00:00:00 2001 From: Daniel Borkmann Date: Wed, 25 May 2022 00:56:18 +0200 Subject: net, neigh: Set lower cap for neigh_managed_work rearming Yuwei reported that plain reuse of DELAY_PROBE_TIME to rearm work queue in neigh_managed_work is problematic if user explicitly configures the DELAY_PROBE_TIME to 0 for a neighbor table. Such misconfig can then hog CPU to 100% processing the system work queue. Instead, set lower interval bound to HZ which is totally sufficient. Yuwei is additionally looking into making the interval separately configurable from DELAY_PROBE_TIME. Reported-by: Yuwei Wang Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/netdev/797c3c53-ce1b-9f60-e253-cda615788f4a@iogearbox.net Reviewed-by: Nikolay Aleksandrov Link: https://lore.kernel.org/r/3b8c5aa906c52c3a8c995d1b2e8ccf650ea7c716.1653432794.git.daniel@iogearbox.net Signed-off-by: Jakub Kicinski --- net/core/neighbour.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'net/core/neighbour.c') diff --git a/net/core/neighbour.c b/net/core/neighbour.c index 47b6c1f0fdbb..54625287ee5b 100644 --- a/net/core/neighbour.c +++ b/net/core/neighbour.c @@ -1579,7 +1579,7 @@ static void neigh_managed_work(struct work_struct *work) list_for_each_entry(neigh, &tbl->managed_list, managed_list) neigh_event_send_probe(neigh, NULL, false); queue_delayed_work(system_power_efficient_wq, &tbl->managed_work, - NEIGH_VAR(&tbl->parms, DELAY_PROBE_TIME)); + max(NEIGH_VAR(&tbl->parms, DELAY_PROBE_TIME), HZ)); write_unlock_bh(&tbl->lock); } -- cgit v1.2.3-59-g8ed1b